Diaphragm pump



April 1931- w. c. CARTER 1,802,136

DIAPHRAGM PUMP Criginal Filed Sept; 28, 1925 AVA A AVAVAVAVAVfiQ UA AVAVAVAUAVA A A Av awn Patented Apr. 21, 1931 UNITED STATES WILLIAM C. CARTER, OF FLINT, MICHIGAN DIAPHRAGM PUMP Original application filed September 28, 1925, Serial No. 59,150. Divided and this application filed October 26, 1928. Serial No. 315,259.

This invention relates to diaphragm pumps of the kind that are used for pumping liquid fuel, my present application being a division of my pending application for Patent Serial No. 59,150, for electrically-operated fuel pumps, filed September 28, 1925.

The main object of my present invention is to provide a non-metallic diaphragm for fuel pumps that will not be rendered inoperative when it is subjected to excessive heat.

Another object is to provide a fuelpump that is equipped with a reservoir of novel construction arranged between the pumping chamber of the pump and a carburetor or similar device to which liquid fuel is being supplied by the pump.

Figure 1 of the drawings is a vertical sectional view of a diaphragm pump embodying my present invention; an

igure 2 is an enlarged cross-sectional view of the diaphragm of said pump.

In the accompanying drawings which illustrate my invention embodied in an electrically-operated fuel pump of the kind described in my pending application for patent previously referred to, A designates the diaphragm of the pump, which is arranged in opposed relation to a rigid cup-shaped member 1, so as to form a pumping chamber 2, the peripheral edge portion of said diaphragm being combined with the member 1 and an opposed clamping member 3 in such a way that the diaphragm will be taut but will be capable of moving towards and away from the wall 1 of the pumping chamber so as to draw liquid fuel into said pumping chamber from a source of supply, and thereafter force the fuel out of said pumping chamber to an internal combustion engine or to a carburetor'or similar device associated with an engine. The pumping chamber 2 is provided with an inlet 4 that is governed by an automatic inlet valve 5 which opens and permits liquid fuel to pass from a source of supply into the chamber 2 during the suc tion stroke or downward stroke of the diaphragm A, and said pumping chamber is prov1ded with an outlet 6 controlled by an automatic discharge valve 7 that opens and permits the fuel to escape from the pumping the opposite direction,

chamber 2 when the diaphragm A flexes in the opposite direction. In the pump herein illustrated the fuel, after escaping from the pumping chamber 2, enters a passageway 8 to which is connected a fuel supply pipe, which, in most instances, will lead to a carburetor (not shown) that is arranged at a lower level than the passageway 8. The pump can either be arranged in a position wherein the diaphragm A is disposed horizontally, as herein shown, or it can be arranged in a position wherein said diaphragm is disposed vertically. 1

Any suitable means can be used for actuating the diaphragm A. In the pump herein shown a spring 9 is used to flex said diaphragm in one direction i. e., upwardly, and a solenoid is used to flex said diaphragm in the solenoid being of the construction described in my said pending application, and comprising a coil B, a core composed of a movable core piece C and a stationary core piece C, and an automatically operating, intermittent switch, designated as an entirety by the reference character D that opens and closes the solenoid circuit intermittently so as to cause the movable core piece C to reciprocate, and thus actuate the diaphragm or pumping element A. As shown inFigure 1 of the drawing, the diaphragm A is connected to the movable core iece C by means of a bolt or screw 10 screwed into the core piece C and arranged with its head in engagement with a clamping plate 11 that clamps the central portion of the diaphragm against a cooperating clamping plate 11 which bears against the upper end of the core piece C. Obviously, any other suitable means may be used to connect the diaphragm A of the pump with the means that actuates the same.

The diaphragm A is constructed in such a way that it will not be rendered inoperative when it is subjected to excessive heat, and it preferably consists of a laminated device composed of one or more laminae of imperforate material, and other laminae of pervious or foraminous material that reinforce the mechanical strength of the diaphragm. In the form of my invention herein shown the diaphragm is composed of an imperforate center layer a: formed of fabric that is treated to render it impervious to water, gasoline and the like, without making it brittle or inflexible, and a plurality of perforated layers 3 formed of treated fabric of the kind mentioned, arranged at opposite sides of said center layer, as shown in Figure 2, so as to protect the same and reinforce the mechanical strength of the diaphragm. The outer laminae or layers 3/ are provided with perforations 12 disposed so as to permit the escape of any gases which may be generated between the layers of the diaphragm in the event the diaphragm is subjected to excessive heat. I have found that in some instances where a diaphragm is composed of a plurality of imperforate layers, eXccssive heat causes gases to be generated between the layers of the diaphragm, which gases cause the diaphragm to swell up or buckle in such a manner that the diaphragm will become practically inflexible and inoperative. To eliminate this I form the diaphragm A from one or more laminae of imperforate material, and other laminae of pervious or foraminous material, whose perforations permit the escape of gases from the spaces between the imperforate and pervious layers of the device, thereby effectively preventing the diaphragm from swelling up and becoming inoperative under excessive or abnormal heat.

In order to insure practically a constant supply of fuel to the carburetor or other devices to which fuel is being supplied by the pump, I equip the pump with a reservoir E that is arranged in communication with the discharge passageway 8 into which fuel is discharged from the pumping chamber 2 at each discharge stroke of the pumping element A. Said reservoir can be 0 any preferred size or capacity and one wall or one portion of said reservoir is formed by a flexible or movable member 13 so as to produce a reservoir from which the fuel will escape freely by gravity at each suction stroke of the pumping element A.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A diaphragm for the purpose described,

composed of an imperforate center layer, and

outer layers arranged at opposite sides of said center layer and provided with perforations, for permitting the escape of gases from the spaces between said layers.

2. A diaphragm for the purpose described composed of a plurality of layers of treated fabric and provided with means which prevents gases which collect in the spaces between the layers from remaining in the said spaces. V

3. A diaphragm for the purpose described composed of a central imperforate layer of treated fabric, and .a plurality of outer layers arranged at opposite sides of said center layer and equipped with perforations that prevent gases from accumulatin and re maining in the spaces between sai layers.

4. A diaphragm for the purpose described, having its peripheral portion embraced by clamping members, and clamping members which engage the central ortion of the diaphragm, said diaphragm being composed of an imperforate layer of treated fabric and additional layers of treated fabric that strengthen and protect said imperforate layer and which are provided with vents to permit the escape of gases from the spaces between said layers.

5. A laminated diaphragm for the purpose described, composed of one or more laminae of imperforate material and other laminae of pervious material that reinforce the mechanical strength of said imperforate material without liability of gases collecting between the laminae of the diaphragm and distorting it.

6. An impervious flexible diaphragm composed of laminations whose peripheral portions are embraced by clamping members, and clamping members which engage the central portion of the diaphragm, one lamina of the diaphragm consistin of foraminous fabric whose openings are arge enough to prevent gases from collecting and remaining in the diaphragm and thus causing it to become distorted.

WILLIAM C. CARTER. 

